The present invention is directed generally to electrical connectors and, more particularly, to connectors employing a bayonet type coupling mechanism and having means to prevent inadvertent uncoupling of the connectors.
One form of conventional electrical connector used today includes a plug and receptacle each of which contains an insulative material carrying a plurality of engageable contacts therein, whereby when the plug and receptacle are fully mated the contacts are engaged to complete an electrical circuit therebetween. A bayonet type connector coupling mechanism is frequently employed to positively retain the plug and receptacle of the connector in the fully mated position.
The bayonet coupling mechanism generally includes bayonet pins projecting radially outwardly from the shell of one of the sections of the connector, frequently the receptacle, which is fixedly connected to a wall, panel or other stationary support. A coupling ring is carried by the other section of the connector, i.e., the plug, and has a corresponding plurality of bayonet tracks therein. The coupling ring has entrance portions at the forward or mating end thereof from which the tracks extend rearwardly, frequently terminating in detent recesses that extend back toward the forward end of the coupling ring. The bayonet pins enters these tracks as the connector is mated and move to the rearward ends of the tracks as the coupling ring is rotated. The coupling mechanism also includes a spring mounted between the coupling ring and the plug which acts to hold the bayonet pins against the detent recesses at the ends of the tracks to retain the coupling ring, plug and receptacle in the fully mated orientation. In addition to providing the positive locking action, the interaction of the bayonet pins and detent recesses provide a positive snapping sound whereby the individual assembling the connector will have both a tactile and an audible confirmation of the electrical connection.
While such an arrangement is generally acceptable, it has been found that under extreme vibration, or after repeated connections and disconnections, the failure rate of the coupling mechanism tends to rise. The vibratory forces cause the pins to disengage from the detent recesses, whereupon the parts might separate due to the spring force, or, alternatively, frequent coupling causes the pins to wear away the detent recesses, particularly under the coupling forces applied by the biasing spring. As the detent recesses wear away, vibration tends to become a more serious problem and tension loads may alone result in the unmating of the connector members.